heayiside



(No Model.)

A. W. HEAVISIDE.

ELEGTRIG WIRE INSULATOR.

No. 402,592. Patented May '7, 1889.

12y]. Fig.3. ibrmA. jbflfl/ B UNITED STATES PATENT OFFICE.

ARTHUR \V. HEAVISIDE, OF NElVCASTLE-UPON-TYNE, ENGLAND.

ELECTRIC-WIRE INSULATOR.

SPECIFICATION forming part of Letters Patent No. 402,592, dated May 7, 1889.

Application filed November 1 2, 1888- Serial No. 290,770. (No model) Patented in England April 20, 1888, No. 5,913.

To aZZ whom it may concern:

Be it known that I, ARTHUR W'Es'r HEAVI- SIDE, a subject of the Queen of Great Britain, residing at \Vhitley, Newcastle-upon-Tyne, England, have invented new and useful Improvements in Insulators for Electric Telegraphs, Telephones, &c., (patented in Great Britain April 20, 1888, No. 5,913,) of which the following is a specification.

My invention has for its object the production of an insulator so constructed as to render the insulation of suspended wires more perfect than is attainable with the insulators ordinarily in use, and to reduce the cost of construction and maintenance of the electric telegraph, telephone, or electric-light wires while facilitating repairs. In order to effect these objects, I support the wire on a bed having a moderate and convenient degree of elasticity in a groove or slot on or across the center of the top of the insulator. The wire is retained in its place by means of a combined. cap and wedge in one piece, which fits round or in the top of the insulator, and can be screwed, clamped, or fastened down tightly upon the wire inclosed in its bed, thus dispensing with the use of binding-wire, which is usually employed for making wires fast to insulators.

In order that my invention may be fully understood, I shall now proceed to more particularly describe the same, and for that purpose shall refer to the two figures on the annexed sheet of drawings, the same letters of reference indicating corresponding parts in the two figures.

Figure 1 represents a vertical sect-ion of an insulator at right angles to the wire it is designed. to support, constructed according to form A of my invention; and Fig. 2, a vertical section (taken at right angles to the wire it is designed to support) of an insulator constructed to the form B of my invention.

A is the insulator proper, composed of porcelain or other suitable material, and carried upon a belt or post, B, made of iron, (for example,) to which the insulator is attached by screwing, by cement, or in any other convenient manner. In the upper part of the insulator A (shown by the dotted lines at C) I provide a vertical slot or groove, in the lower end of which the wire I) rests on an elastic ally-yielding bed. For example, it may be enveloped in. a piece of india-rubber or vulcanite piping. The wire is held in position at the lower end. of the slot or groove O by means of a combined cap and wedge, F, which is screwed on outside the top of the insulator. The combined cap and wedge may be made of pottery or metal, but preferably of insulite, ebonite, hard wood, or any substance not so brittle and more manageable than pottery.

The form shown in Fig. 2 differs from form A in the screw of the cap F being made to combine the functions of the screw and wedge of form A. This is effected by screwing the cap inside the top of the insulatorA, as shown.

Itis obvious that many variations in size and shape may be made in both form A and B 5 but Figs. 1 and 2 substantially show the mode in which my invention is carried out.

It will be observed that the function or duty of the central projection, g, of the capgvhether conical or not and whether screw-threaded or not, is to clamp, press, or wedge the wire down, and that it turns in the cavity provided for it in the body of the insulator.

By the use of my said invention the follow ing advantages are obtained, viz:

First. Economy in manufacture, simplicity, and lightness in construction, combined with increased strength.

Second. Saving of labor, time, and expense in running telegraph or other wires from support to support and fixing them at each support as compared with the present method, as the slot forms its own pulley or sheave for the wire to run through, and thus avoids abrasion, and no wire-bindings or iron or other guards are required to keep the wire in position.

Third. Increased stability and prolonged life of the wire, especially of the copper wire so much in use at the present time, from the presence of the bed, which checks vibration, and the absence of the generallyaised binding-wire,which pulls the wire out of line, tending to kink it and in time cause it to break.

Fourth. Enabling insulators to be washed in dirty districts without the loss of time caused. by unfastening the binding-wire and the loss of material caused by the necessary employment of a new binder each time a binder is removed.

Fifth. Greaterpower of resisting any stress brought to hearon thewire by wind or snow from having a direct bearing upon the point of support i. e.,the center of the insulator.

Sixth. More perfect insulation through the superficial contact of the wire with the insu- 5 lator being confined to the wire itself, whereas where binders are used the contactis extended all round the insulator.

Seventh. Perfect avoidance of chafing between the insulator and the line-wire, which 10 eventually leads to the fracture of the linewire at'or near the point of chafe.

Eighthl'lhe great convenience of having the cap and wedge in one piece and made of a material in which lightness and strength are 15 combined, and which is not liable to fracture through brittleness.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed,

20 I declare that what I claim is 1. A screw-cap for insulators, having a central projection, combined with an insulator having a central cavity to receive such projection and provided with a vertical slot to receive the Wire, both the cap and insulator 5 being screw threaded, and the cap being adapted, when screwed home, to exert apressure upon the wire, substantially as set forth.

2. A screw-cap for insulators, made with a central projection having an exterior thread, 0 in combination with an insulator having a corresponding interior thread and a vertical slot to receive the wire, and adapted, when screwed home, to exert a pressure upon the wire inclosed in an elastic envelope or bed, substan- 3 5 tially as set forth.

A. W. HEAVISIDE.

Witnesses:

THOMAS WAI'rn, .loHN Hnsxn'rn. 

